Abstract: Objective:To explore the effects and mechanism of dendritic cells(DC) induced by nuclear factor-B(NF-B) oligodeoxynucleotide(ODN) in rats with type Ⅱ collagen-induced arthritis(CIA).Methods:The model rats with arthritic were established by type Ⅱ collagen inducing.DC from rat spleen treated with NF-B ODN were injected to caudal vein of CIA rats at 5 days after the initial immunization.The change of paw-swelling,the index of arthritis and pathogenic indicator of the control group,CIA model group and experimental group were observed after 42 days.Results:The OX62 expression on the DC surface of three groups were above 70%,there was no significant difference(P0.05).The CD80 postive cells of CIA model group and experimental group had significant difference(P0.01).The CD80 and CD86 average fluorescence intensity of experimental group was significantly higher than that of CIA model group(P0.01).At 7 days primary immune,the arthritis index of CIA model group and experimental group began to increase,the arthritis index of experimental group were significantly lower than that of CIA model group at 21 days(P0.01).Conclusions:The DC induced by NF-B ODN can effectively relieve the arthritis symptoms and histopathology damage of CIA rats,and have good curative effects on rheumatoid arthritis.